<?php

$string = 'hello world 中国';

echo "hhh, ${string}";

echo "可以\\\"雨天\"";

echo "真不错\t\naaaaaaaaaaaaaaaaaa\naaaaaaaaaaaaaaaaaaaaaaaaa\naaaaaaaaaaaaaaaaaaaaa";

// 定界符
$str = <<<php
<h1>aaaaaa</h1>
php;
echo $str;

$str2 = 'hello world';
$str3 = 'js';
echo $str2.$str3;
echo strlen($str2);
echo strlen('中国');
echo mb_strlen('中国', 'utf8');
